1. Field of the Invention
The present invention relates to a seatbelt system for restraining bodies of vehicle occupants, and more specifically to a webbing retractor of a long strip-shaped webbing belt.
2. Description of the Related Art
In a long strip-shaped webbing belt structuring a seatbelt system for a vehicle, a longitudinal base end thereof is engaged to a spool of a webbing retractor. When the spool is rotated in a take-up direction that is one direction around its own axis, the webbing belt is taken up and stored by the spool.
In this kind of a webbing retractor, a lock mechanism that regulates the rotation of the spool in a pull-out direction that is opposite to the take-up direction and thereby limits the pull-out action of the webbing belt.
As an aspect of such a lock mechanism, there is known an emergency locking retractor mechanism (hereinafter referred to as “ELR mechanism”) that detects a rapid deceleration condition of a vehicle and regulates the rotation of the spool in the pull-out direction. Further, there is also known an automatic locking retractor (hereinafter referred to as “ALR mechanism”) that is different from the ELR mechanism and regulates the rotation of the spool in the pull-out direction irrespective of the vehicle's conditions when the webbing belt is attached.
An example of a webbing retractor having both the ELR mechanism and the ALR mechanism is disclosed in Japanese Utility Model Application Laid-Open (JP-U) No. 03-121059.
The webbing retractor disclosed in JP-U No. 03-121059 has a lock ring. The lock ring is arranged coaxially and relatively rotatably to the spool and rotates in compliance with the spool that rotates by urging force of an urging member. However, when the lock ring cannot follow the spool rotating in the pull-out direction, there occurs a relative rotation between the spool and the lock ring, and a lock means works to regulate the rotation of the spool in the pull-out direction.
The ALR lever of the webbing retractor disclosed in the above document is arranged so as to reciprocate between its engaging position and its retreat position retreated from the engaging position. The ALR lever moves to the engaging position to engage with the lock ring thereby regulates the rotation of the lock ring in the pull-out direction.
The ALR lever is reciprocated by a release gear between the engaging position and the retreat position. The release gear is a deceleration gear coupled to the rotation of the spool, and makes its one rotation around the spool by coupling with the spool rotations between an entirely stored condition where the webbing belt is taken up and stored and an entirely pulled-out condition where the webbing belt is entirely pulled out.
In the release gear, a cam and the like are formed. When the spool rotates in the pull-out direction until just before the entirely pulled-out condition, the cam and the like engage with the ALR lever, and when the spool rotates in the pull-out direction further in this condition, the cam and the like in combination with this rotation press the ALR lever to move it to the engaging position.
Further, when the spool rotates in the take-up direction until just before the entirely stored condition, the above cam and the like or a different release cum and the like formed on the release gear engage with the ALR lever, and when the spool rotates in the take-up direction further in this condition, the release cam and the like press the ALR lever to move it to the retreat position.
In the above-described webbing retractor, the engaging relation between the release gear and the ALR lever is so set that the ALR lever moves to the engaging position when the webbing belt is in its condition just before the entirely pulled-out condition.
There is another structure where the ALR lever moves to the engaging position when the spool rotates in the take-up direction at a specified angle after the webbing belt gets in its entirely pulled-out condition.
The seatbelt system is assembled into a vehicle in a condition where the webbing belt is entirely pulled out from the spool, and after the assembly, the webbing belt is taken up by the spool.
When the webbing retractor is assembled into a vehicle, the webbing belt is entirely pulled out by locating the cam and the like of the release gear at a temporary position where the webbing belt can be entirely pulled out, then the assembly is carried out.
Meanwhile, after the assembly, the cam and the like of the release gear contact the ALR lever in the condition where the webbing belt is just before entirely pulled-out and the cum and the like do not further move in the pull-out direction of the webbing belt. Namely, in the webbing retractor of such a structure, after assembly, the webbing belt cannot be entirely pulled out from the spool.
Accordingly, in such a webbing retractor, in a condition where occupants and the like of a vehicle recognize that the webbing belt is entirely pulled out (hereinafter referred to as “a surface entirely pulled-out condition”), there is actually a part of the webbing belt left in the spool, therefore, it is necessary to set the full length of the webbing belt longer in its manufacture.